1. Field of the Invention
The present invention relates to an optical connector used to optically connect an optical component and an optical coupling structure using the optical connector.
2. Related Background Art
In general, an optical fiber cable is optically connected to an optical component through an optical connector that is attached to an end portion of the optical fiber cable. The diameter of an optical fiber is about 0.125 mm. Since the connection loss increases unless the core portion of the optical fiber is accurately positioned, the optical connector and opposite-side optical component must be positioned to each other very accurately. For this reason, in optical connection using the above optical. connector, the optical connector and opposite-side optical component are accurately positioned to each other with guide pins.
An end portion of the optical fiber is placed on the optical connecting surface of the optical connector, and a pair of pin insertion holes for insertion of the guide pins are formed in the optical connecting surface.
Accordingly, end portions of the optical fiber and optical waveguide, optical elements, and the like are arranged on the optical connecting surface of the opposite-side optical component, and a pair of pin insertion holes for the insertion of the guide pins are formed in the optical connecting surface. In optical connection, the guide pins are respectively inserted into the pin insertion holes on the optical connector side to protrude from the optical connecting surface. When the protruding guide pins are inserted into the guide pin insertion holes of the opposite-side optical component, the end face of the optical fiber placed on the optical connecting surface of the optical connector is accurately positioned to the end face of the optical fiber of the opposite-side optical component, optical waveguide, optical elements, and the like.
According to an optical connector like the one described above, when an operator or the like attaches the optical connector, from which the guide pins protrude, to an opposite-side optical component, the distal ends of the guide pins sometimes damage the optical connecting surface of the opposite-side optical component, pin insertion holes, or the end faces of optical fibers. If the optical connecting surface or pin insertion holes are damaged, the guide pins rattle or dust or the like is produced. This makes it impossible to align optical fibers with high precision. In addition, if the end faces of optical fibers are damaged, the connection loss inevitably increases. Furthermore, when the operator or the like inserts the guide pins into the pin insertion holes of the opposite-side optical component or removes the guide pins therefrom, the pin insertion holes are scratched and damaged in some cases. Since the guide pins protrude from the optical connecting surface, the optical connecting surface is not easy to clean.
The present invention has been made in consideration of the above points, and has as its object to provide an optical connector that allows high-precision alignment without damaging an opposite-side optical component.
An optical connector according to the present invention is characterized by comprising a ferrule having an optical connecting surface with which an opposite-side optical component is brought into contact, and a pair of guide pins for aligning with the opposite-side optical component, wherein at least one fiber insertion hole into which an optical fiber is inserted and a pair of pin insertion holes into which the pair of guide pins are slidably inserted are formed in the ferrule, one end portion of the fiber insertion hole and one end portion of each of the pin insertion holes are open to the optical connecting surface, and each of the pair of guide pins has a total length larger than a total length of each of the pin insertion holes, the guide pins are coupled to each other on one end portion thereof, axial positions of the guide pins can be arbitrarily changed from outside, and other ends of the guide pins can be accommodated in the pin insertion holes by sliding the guide pins.
According to the optical connector of the present invention, the other ends of the guide pins can be accommodated in the pin insertion holes without making the other ends protrude from the optical connecting surface, and the optical connecting surface of the ferrule can be aligned to the opposite-side optical component with high precision by sliding the guide pins after bringing the optical connecting surface into contact with the opposite-side optical component. This makes it possible to prevent the other ends of the guide pins from damaging the opposite-side optical component in an optical connection process. In addition, the optical connecting surface can be easily cleaned. Furthermore, since the guide pins are slid after the optical connecting surface of the ferrule is brought into contact with-the opposite-side optical component, the guide pins do not scratch the opposite-side optical component in an optical connection process, thereby preventing damage to the opposite-side optical component.
According to the optical connector of the present invention, the other ends of the guide pins are accommodated in the pin insertion holes without making the other ends protrude from the optical connecting surface, and alignment is performed with high precision by sliding the guide pins after bringing the optical connecting surface of the ferrule into contact with the optical connecting surface of the opposite-side optical component. This makes it possible to perform optical connection without sliding the optical connector itself. As a consequence, the degree of freedom in disposing the optical connector and opposite-side optical component increases, and the space efficiency around the optical connector improves. And furthermore, it is possible to decrease a bend-of the optical fiber because the optical connector doesn""t slide in the direction of the optical axis of the optical fiber.
An optical connector according to the present invention is characterized by comprising a ferrule having an optical connecting surface with which an opposite-side optical component is brought into contact, and a pair of guide pins for positioning with respect to the opposite-side optical component, wherein at least one fiber insertion hole into which an optical fiber is inserted and a pair of pin insertion holes into which the pair of guide pins are slidably inserted are formed in the ferrule, one end portion of the fiber insertion hole and one end portion of each of the pin insertion holes are open to the optical connecting surface, and each of the pair of guide pins has a total length larger than a total length of each of the pin insertion holes, and the guide pins are coupled to each other on one end portion thereof, the ferrule and the pair of guide pins can relatively move, and the optical connecting surface of the ferrule is located at an extreme tip-portion when viewed from an optical axis direction of the optical fiber while the opposite-side optical component is not connected.
According to the optical connector of the present invention, the ferrule and the pair of guide pins can move relative to each other. When the optical connecting surface of the ferrule is located at the extreme tip portion when viewed from the optical axis direction of optical fibers while the opposite-side optical component is not connected, the optical connecting surface of the ferrule can be brought into contact with the opposite-side optical component while the other ends of the guide pins are accommodated in the pin insertion holes without making the other ends protrude from the optical connecting surface. This makes it possible to prevent the other ends of the guide pins from damaging the opposite-side optical component in an optical connection process and facilitate cleaning the optical connecting surface.
According to the optical connector of the present invention, when an opposite-side optical component is mounted on a board, the optical connector can be transferred from above the board. This facilitates optical connection of the optical connector to the opposite-side optical component mounted on the board.
Preferably, this connector further comprises pin locking means for locking the pair of guide pins while the other ends of the pair of guide pins are accommodated in the pin insertion holes. With this arrangement, the other ends of the guide pins can be kept accommodated in the pin insertion holes, and the other ends of the guide pins can be prevented from accidentally protruding from the optical connecting surface in an optical connection process. This facilitates an optical connection process and prevents damage to the opposite-side optical component.
Preferably, this connector further comprises pin removal preventing means for preventing the pair of guide pins from falling off from the pin insertion holes. With this arrangement, removal of the guide pins from the pin insertion holes can be prevented more reliably. This makes it possible to eliminate a hindrance to a connection process due to removal of the guide pins before optical connection and reliably. maintain the optical connection state after optical connection.
A chamfered portion is preferably formed on at least a portion of an edge portion of the optical connecting surface. This can prevent a portion near the optical connecting surface of the optical connector from straddling the opposite-side optical component and facilitate an optical connection process. In addition, damage to the portion near the optical connecting surface can be prevented.
Preferably, this connector further comprises pin fixing means for fixing the pair of guide pins while. the other ends of the pair of guide pins protrude from the optical connecting surface. With this arrangement, since the guide pins protruding from the optical connecting surface can be reliably fixed, the accurately aligned state after optical connection can be maintained.
Preferably, this connector further comprises a coupling member for coupling the pair of guide pins on the one end portion of the pair of guide pins thereof, and a spring disposed between the coupling member and the ferrule, and the spring biases the ferrule to press the optical connecting surface of the ferrule against the optical connecting surface of the opposite-side optical component. With this arrangement, the guide pins can be inserted into the opposite-side optical component while the biasing force of the spring on the ferrule is small, thereby making the guide pins float more properly.
An optical connector according to the present invention is characterized by comprising a ferrule having an optical connecting surface with which an opposite-side optical component is brought into contact, and a pair of guide pins for positioning with respect to the opposite-side optical component, wherein at least one fiber insertion hole into which an optical fiber is inserted and a pair of pin insertion holes into which the pair of guide pins are slidably inserted are formed in the ferrule, one end portion of the fiber insertion hole and one end portion of each of the pin insertion holes are open to the optical connecting surface, and each of the pair of guide pins has a total length larger than a total length of each of the pin insertion holes, the guide pins are coupled to each other on one end portion thereof, a sliding position of the guide pins can be arbitrarily changed, and other ends of the guide pins can be accommodated in the pin insertion holes by sliding the guide pins, and the optical connecting surface of the ferrule is located at an extreme tip portion when viewed from an optical axis direction of the optical fiber while the other ends of the pair of guide pins are accommodated in the pin insertion holes.
According to the optical connector of the present invention, the optical connecting surface of the ferrule is brought into contact with the opposite-side optical component while the other ends of the guide pins are accommodated in the pin insertion holes without making the other ends protrude from the optical connecting surface. After the optical connecting surface is brought into contact with the opposite-side optical component, high-precision alignment can be performed by sliding the guide pins. This can prevent the other ends of the guide pins from damaging the opposite-side optical component in an optical connection process. In addition, the optical connecting surface can be easily cleaned. Furthermore, since the guide pins are slid after the optical connecting surface of the ferrule is brought into contact with the optical connecting surface of the opposite-side optical component, the guide pins do not scratch the opposite-side optical component in an optical connection process, thereby preventing damage to the opposite-side optical component.
In addition, the other ends of the guide pins are accommodated in the pin insertion holes without making the other ends protruding from the optical connecting surface, and the optical connecting surface of the ferrule is brought into contact with the optical connecting surface of the opposite-side optical component. Thereafter, high-precision alignment is performed by sliding the guide pins. This makes it possible to perform optical connection without sliding the optical connector itself. As a consequence, the degree of freedom in disposing the optical connector and opposite-side optical component increases, and the space efficiency around the optical connector improves. And furthermore, it is possible to decrease a bend of the optical fiber because the optical connector doesn""t slide in the direction of the optical axis of the optical fiber.
An optical coupling structure according to the present invention is an optical coupling structure for optically coupling the optical connector defined in claim 1 or 8 to an optical module surface-mounted on a board, characterized in that the optical module includes an optical connecting surface with which an optical connecting surface of the ferrule is brought into contact, and an extended portion extended in a direction substantially perpendicular to an optical fiber accommodated in the ferrule, and the optical connector or a portion thereof and the extended portion are clamped by a clamp member.
According to the optical coupling structure of the present invention, the optical connector (or its portion) and the extended portions of the optical modules are clamped by the clamp member to bring the optical connecting surfaces of the ferrule and optical module into contact with each other. For this reason, the force that brings the optical connecting surfaces of the ferrule and optical module into contact with each other does not act on the main body of the optical module. This makes it possible to prevent damage to the optical module and maintain a stably optically coupled state.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not to be considered as limiting the present invention.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.